C++ Epetra_Comm类代码示例

void random_distribution_1D(
  itype nrows,          // Number of global matrix rows
  Epetra_Comm &comm,    // Epetra communicator to be used in maps
  Epetra_Map **rowMap,  // OUTPUT: pointer to row map to be created
  long long offsetEpetra64
) 
{
  // Randomly assign matrix rows to processor's row Map.

  int me = comm.MyPID();
  int np = comm.NumProc();

  vector<itype> myGlobalElements(1.2 * (nrows / np) + 1);
  int nMyRows = 0;
  srandom(1);
  double denom = (double) RAND_MAX + 1.;
  for (itype i = 0; i < nrows; i++) {
    int p = (int) ((double) np * (double) random() / denom);
    if (p == me) {
      if (nMyRows >= myGlobalElements.size()) 
        myGlobalElements.resize(1.5*myGlobalElements.size());
      myGlobalElements[nMyRows] = i + offsetEpetra64;
      nMyRows++;
    }
  }
  *rowMap = new Epetra_Map(nrows, nMyRows, &myGlobalElements[0], 0, comm);
}

bool global_check_for_flag_on_proc_0(const char* flag,
                                     int numargs,
                                     char** strargs,
                                     const Epetra_Comm& comm)
{
    int mypid = comm.MyPID();
    int numprocs = comm.NumProc();

    int flag_found = 0;
    if (mypid==0) {
        for(int i=0; i<numargs; ++i) {
            if (strargs[i]==0) continue;

            if (strcmp(flag, strargs[i]) == 0) {
                flag_found = 1;
                break;
            }
        }
    }

    if (numprocs > 1) {
        comm.Broadcast(&flag_found, 1, 0);
    }

    bool return_value = flag_found==1 ? true : false;

    return( return_value );
}

int fevec6(Epetra_Comm& Comm, bool verbose)
{
  int NumElements = 4;
  Epetra_Map     Map(NumElements, 0, Comm);
  Epetra_FEVector x1(Map);
  x1.PutScalar (0);

        // let all processors set global entry 0 to 1
  const int GID = 0;
  const double value = 1;
  x1.ReplaceGlobalValues(1, &GID, &value);
  x1.GlobalAssemble (Insert);
  if (Comm.MyPID()==0)
    std::cout << "Entry " << GID << " after construct & set: " 
        << x1[0][0] << std::endl;

  x1.PutScalar(0);

        // re-apply 1 to the vector, but only on the
        // owning processor. should be enough to set
        // the value (as non-local data in x1 should
        // have been eliminated after calling
        // GlobalAssemble).
  if (Comm.MyPID()==0)
    x1.ReplaceGlobalValues(1, &GID, &value);
  x1.GlobalAssemble (Insert);

  if (Comm.MyPID()==0) {
    std::cout << "Entry " << GID << " after PutScalar & set:      " 
        << x1[0][0] << std::endl;
    if (x1[0][0] != value) return -1;
  }

  return 0;
}

void ML_Read_Matrix_Dimensions(const char *filename, int *numGlobalRows, Epetra_Comm &Comm)
{
    char line[35], token1[35], token2[35], token3[35], token4[35], token5[35];
    int lineLength = 1025;
    FILE *fid = fopen(filename,"r");
    int N, NZ;
    if(fgets(line, lineLength, fid)==0) {
      if (fid!=0) fclose(fid);
      ML_Exit(Comm.MyPID(),"error opening matrix file", EXIT_FAILURE);
    }
    if(sscanf(line, "%s %s %s %s %s", token1, token2, token3, token4, token5 )==0) {
      if (fid!=0) fclose(fid);
      ML_Exit(Comm.MyPID(),"error reading matrix file header", EXIT_FAILURE);
    }
    if (strcmp(token1, "%%MatrixMarket") || strcmp(token2, "matrix") ||
        strcmp(token3, "coordinate") || strcmp(token4, "real") ||
        strcmp(token5, "general"))
    {
      if (fid!=0) fclose(fid);
      ML_Exit(Comm.MyPID(),"error reading matrix file header", EXIT_FAILURE);
    }
    // Next, strip off header lines (which start with "%")
    do {
      if(fgets(line, lineLength, fid)==0) {
        if (fid!=0) fclose(fid);
        ML_Exit(Comm.MyPID(),"error reading matrix file comments", EXIT_FAILURE);
      }
    } while (line[0] == '%');

    // Next get problem dimensions: M, N, NZ
    if(sscanf(line, "%d %d %d", numGlobalRows, &N, &NZ)==0) {
      if (fid!=0) fclose(fid);
      ML_Exit(Comm.MyPID(),"error reading matrix file dimensions", EXIT_FAILURE);
    }
} //ML_Read_Matrix_Dimensions()

void show_matrix(const char *txt, const Epetra_RowMatrix &matrix, const Epetra_Comm &comm)
{
  int me = comm.MyPID();
  if (comm.NumProc() > 10){
    if (me == 0){
      std::cout << txt << std::endl;
      std::cout << "Printed matrix format only works for 10 or fewer processes" << std::endl;
    }
    return;
  }

  int numRows = matrix.NumGlobalRows();
  int numCols = matrix.NumGlobalCols();

  if ((numRows > 200) || (numCols > 500)){
    if (me == 0){
      std::cerr << txt << std::endl;
      std::cerr << "show_matrix: problem is too large to display" << std::endl;
    }
    return;
  }

  int *myA = new int [numRows * numCols];

  make_my_A(matrix, myA, comm);

  printMatrix(txt, myA, NULL, NULL, numRows, numCols, comm);

  delete [] myA;
}

int generateHyprePrintOut(const char *filename, const Epetra_Comm &comm){
  int MyPID = comm.MyPID();
  int NumProc = comm.NumProc();

  int N = 100;
  int ilower = MyPID * N;
  int iupper = (MyPID+1)*N-1;

  double filePID = (double)MyPID/(double)100000;
  std::ostringstream stream;
  // Using setprecision() puts it in the std::string
  stream << std::setiosflags(std::ios::fixed) << std::setprecision(5) << filePID;
  // Then just ignore the first character
  std::string fileName(filename);
  fileName += stream.str().substr(1,7);

  std::ofstream myfile(fileName.c_str());

  if(myfile.is_open()){
    myfile << ilower << " " << iupper << " " << ilower << " " << iupper << std::endl;
    for(int i = ilower; i <= iupper; i++){
      for(int j=i-5; j <= i+5; j++){
        if(j >= 0 && j < N*NumProc)
          myfile << i << " " << j << " " << (double)rand()/(double)RAND_MAX << std::endl;
      }
    }
    myfile.close();
    return 0;
  } else {
    std::cout << "\nERROR:\nCouldn't open file.\n";
    return -1;
  }
}

int special_submap_import_test(Epetra_Comm& Comm)
{
  int localProc = Comm.MyPID();

  //set up ids_source and ids_target such that ids_source are only
  //a subset of ids_target, and furthermore that ids_target are ordered
  //such that the LIDs don't match up. In other words, even if gid 2 does
  //exist in both ids_source and ids_target, it will correspond to different
  //LIDs on at least 1 proc.
  //
  //This is to test a certain bug-fix in Epetra_Import where the 'RemoteLIDs'
  //array wasn't being calculated correctly on all procs.

  long long ids_source[1];
  ids_source[0] = localProc*2+2;

  long long ids_target[3];
  ids_target[0] = localProc*2+2;
  ids_target[1] = localProc*2+1;
  ids_target[2] = localProc*2+0;

  Epetra_Map map_source((long long) -1, 1, &ids_source[0], 0LL, Comm);
  Epetra_Map map_target((long long) -1, 3, &ids_target[0], 0LL, Comm);

  Epetra_Import importer(map_target, map_source);

  Epetra_LongLongVector vec_source(map_source);
  Epetra_LongLongVector vec_target(map_target);

  vec_target.PutValue(0);

  //set vec_source's contents so that entry[i] == GID[i].
  long long* GIDs = map_source.MyGlobalElements64();
  for(int i=0; i<map_source.NumMyElements(); ++i) {
    vec_source[i] = GIDs[i];
  }

  //Import vec_source into vec_target. This should result in the contents
  //of vec_target remaining 0 for the entries that don't exist in vec_source,
  //and other entries should be equal to the corresponding GID in the map.

  vec_target.Import(vec_source, importer, Insert);

  GIDs = map_target.MyGlobalElements64();
  int test_failed = 0;

  //the test passes if the i-th entry in vec_target equals either 0 or
  //GIDs[i].
  for(int i=0; i<vec_target.MyLength(); ++i) {
    if (vec_target[i] != GIDs[i] && vec_target[i] != 0) test_failed = 1;
  }

  int global_result;
  Comm.MaxAll(&test_failed, &global_result, 1);

  //If test didn't fail on any procs, global_result should be 0.
  //If test failed on any proc, global_result should be 1.
  return global_result;
}

//==============================================================================
Poisson2dOperator::Poisson2dOperator(int nx, int ny, const Epetra_Comm & comm)
    : nx_(nx),
      ny_(ny),
      useTranspose_(false),
      comm_(comm),
      map_(0),
      numImports_(0),
      importIDs_(0),
      importMap_(0),
      importer_(0),
      importX_(0),
      Label_(0) {

    Label_ = "2D Poisson Operator";
    int numProc = comm.NumProc(); // Get number of processors
    int myPID = comm.MyPID(); // My rank
    if (2*numProc > ny) { // ny must be >= 2*numProc (to avoid degenerate cases)
        ny = 2*numProc;
        ny_ = ny;
        std::cout << " Increasing ny to " << ny << " to avoid degenerate distribution on " << numProc << " processors." << std::endl;
    }

    int chunkSize = ny/numProc;
    int remainder = ny%numProc;

    if (myPID+1 <= remainder) chunkSize++; // add on remainder

    myny_ = chunkSize;

    map_ = new Epetra_Map(-1LL, ((long long)nx)*chunkSize, 0, comm_);

    if (numProc>1) {
        // Build import GID list to build import map and importer
        if (myPID>0) numImports_ += nx;
        if (myPID+1<numProc) numImports_ += nx;

        if (numImports_>0) importIDs_ = new long long[numImports_];
        long long * ptr = importIDs_;
        long long minGID = map_->MinMyGID64();
        long long maxGID = map_->MaxMyGID64();

        if (myPID>0) for (int i=0; i< nx; i++) *ptr++ = minGID - nx + i;
        if (myPID+1<numProc) for (int i=0; i< nx; i++) *ptr++ = maxGID + i +1;

        // At the end of the above step importIDs_ will have a list of global IDs that are needed
        // to compute the matrix multiplication operation on this processor.  Now build import map
        // and importer


        importMap_ = new Epetra_Map(-1LL, numImports_, importIDs_, 0LL, comm_);

        importer_ = new Epetra_Import(*importMap_, *map_);

    }
}

int alternate_import_constructor_test(Epetra_Comm& Comm) {
  int rv=0;
  int nodes_per_proc=10;
  int numprocs = Comm.NumProc();
  int mypid    = Comm.MyPID();

  // Only run if we have multiple procs & MPI
  if(numprocs==0) return 0;
#ifndef HAVE_MPI
  return 0;
#endif

  // Build Map 1 - linear
  Epetra_Map Map1((long long)-1,nodes_per_proc,(long long)0,Comm);

  // Build Map 2 - mod striped
  std::vector<long long> MyGIDs(nodes_per_proc);
  for(int i=0; i<nodes_per_proc; i++)
    MyGIDs[i] = (mypid*nodes_per_proc + i) % numprocs;
  Epetra_Map Map2((long long)-1,nodes_per_proc,&MyGIDs[0],(long long)0,Comm);

  // For testing
  Epetra_LongLongVector Source(Map1), Target(Map2);


  // Build Import 1 - normal
  Epetra_Import Import1(Map2,Map1);
  rv = rv|| test_import_gid("Alt test: 2 map constructor",Source,Target, Import1);

  // Build Import 2 - no-comm constructor
  int Nremote=Import1.NumRemoteIDs();
  const int * RemoteLIDs = Import1.RemoteLIDs();
  std::vector<int> RemotePIDs(Nremote+1); // I hate you, stl vector....
  std::vector<int> AllPIDs;
  Epetra_Util::GetPids(Import1,AllPIDs,true);

  for(int i=0; i<Nremote; i++) {
    RemotePIDs[i]=AllPIDs[RemoteLIDs[i]];
  }
  Epetra_Import Import2(Import1.TargetMap(),Import1.SourceMap(),Nremote,&RemotePIDs[0],Import1.NumExportIDs(),Import1.ExportLIDs(),Import1.ExportPIDs());

  rv = rv || test_import_gid("Alt test: no comm constructor",Source,Target,Import2);


  // Build Import 3 - Remotes only
  Epetra_Import Import3(Import1.TargetMap(),Import1.SourceMap(),Nremote,&RemotePIDs[0]);
  rv = rv || test_import_gid("Alt test: remote only constructor",Source,Target, Import3);


  return rv;
}

int combine_mode_test(Epetra_Comm& Comm)
{
  int localProc = Comm.MyPID();


  long long ids_source[1];
  ids_source[0] = localProc*2+2;

  long long ids_target[3];
  ids_target[0] = localProc*2+2;
  ids_target[1] = localProc*2+1;
  ids_target[2] = localProc*2+0;

  Epetra_Map map_source((long long) -1, 1, &ids_source[0], 0LL, Comm);
  Epetra_Map map_target((long long) -1, 3, &ids_target[0], 0LL, Comm);

  Epetra_Import importer(map_target, map_source);

  Epetra_LongLongVector vec_source(map_source);
  Epetra_LongLongVector vec_target(map_target);

  vec_target.PutValue(0);

  //set vec_source's contents so that entry[i] == GID[i].
  long long* GIDs = map_source.MyGlobalElements64();
  for(int i=0; i<map_source.NumMyElements(); ++i) {
    vec_source[i] = GIDs[i];
  }

  //Import vec_source into vec_target. This should result in the contents
  //of vec_target remaining 0 for the entries that don't exist in vec_source,
  //and other entries should be equal to the corresponding GID in the map.

  vec_target.Import(vec_source, importer, Insert);

  GIDs = map_target.MyGlobalElements64();
  int test_failed = 0;

  //the test passes if the i-th entry in vec_target equals either 0 or
  //GIDs[i].
  for(int i=0; i<vec_target.MyLength(); ++i) {
    if (vec_target[i] != GIDs[i] && vec_target[i] != 0) test_failed = 1;
  }

  int global_result;
  Comm.MaxAll(&test_failed, &global_result, 1);

  //If test didn't fail on any procs, global_result should be 0.
  //If test failed on any proc, global_result should be 1.
  return global_result;
}

//==============================================================================
// Epetra_BlockMap constructor function for a Epetra-defined uniform linear distribution of constant size elements.
void Epetra_BlockMap::ConstructAutoUniform(long long NumGlobal_Elements, int Element_Size, int Index_Base, const Epetra_Comm& comm, bool IsLongLong)
{
  
  // Each processor gets roughly numGlobalPoints/p points
  // This routine automatically defines a linear partitioning of a
  // map with numGlobalPoints across the processors
  // specified in the given Epetra_Comm
  
  if (NumGlobal_Elements < 0) 
    throw ReportError("NumGlobal_Elements = " + toString(NumGlobal_Elements) + ".  Should be >= 0.", -1);
  if (Element_Size <= 0) 
    throw ReportError("ElementSize = " + toString(Element_Size) + ".  Should be > 0.", -2);
  
  BlockMapData_ = new Epetra_BlockMapData(NumGlobal_Elements, Element_Size, Index_Base, comm, IsLongLong);
  int NumProc = comm.NumProc();
  BlockMapData_->ConstantElementSize_ = true;
  BlockMapData_->LinearMap_ = true;

  int MyPID = comm.MyPID();

  if(BlockMapData_->NumGlobalElements_ / NumProc > (long long) std::numeric_limits<int>::max())
    throw ReportError("Epetra_BlockMap::ConstructAutoUniform: Error. Not enough space for elements on each processor", -99);

  BlockMapData_->NumMyElements_ = (int) (BlockMapData_->NumGlobalElements_ / NumProc);
  int remainder = (int) (BlockMapData_->NumGlobalElements_ % NumProc); // remainder will fit int
  int start_index = MyPID * (BlockMapData_->NumMyElements_ + 1);

  if (MyPID < remainder) 
    BlockMapData_->NumMyElements_++;
  else 
    start_index -= (MyPID - remainder);

  BlockMapData_->NumGlobalPoints_ = BlockMapData_->NumGlobalElements_ * BlockMapData_->ElementSize_;
  BlockMapData_->NumMyPoints_ = BlockMapData_->NumMyElements_ * BlockMapData_->ElementSize_;

  BlockMapData_->MinMyElementSize_ = BlockMapData_->ElementSize_;
  BlockMapData_->MaxMyElementSize_ = BlockMapData_->ElementSize_;
  BlockMapData_->MinElementSize_ = BlockMapData_->ElementSize_;
  BlockMapData_->MaxElementSize_ = BlockMapData_->ElementSize_;

  BlockMapData_->MinAllGID_ = BlockMapData_->IndexBase_;
  BlockMapData_->MaxAllGID_ = BlockMapData_->MinAllGID_ + BlockMapData_->NumGlobalElements_ - 1;
  BlockMapData_->MinMyGID_ = start_index + BlockMapData_->IndexBase_;
  BlockMapData_->MaxMyGID_ = BlockMapData_->MinMyGID_ + BlockMapData_->NumMyElements_ - 1;
  BlockMapData_->DistributedGlobal_ = IsDistributedGlobal(BlockMapData_->NumGlobalElements_, BlockMapData_->NumMyElements_);

  EndOfConstructorOps();
}

int rebalanceEpetraProblem( RCP<Epetra_Map>         &Map,
                            RCP<Epetra_CrsMatrix>   &A,
                            RCP<Epetra_MultiVector> &B,
                            RCP<Epetra_MultiVector> &X,
                            Epetra_Comm             &Comm
                          )
{
  // Rebalance linear system across multiple processors.
  if ( Comm.NumProc() > 1 ) {
    RCP<Epetra_Map> newMap = rcp( new Epetra_Map( Map->NumGlobalElements(), Map->IndexBase(), Comm ) );
    RCP<Epetra_Import> newImport = rcp( new Epetra_Import( *newMap, *Map ) );

    // Create rebalanced versions of the linear system.
    RCP<Epetra_CrsMatrix> newA = rcp( new Epetra_CrsMatrix( BELOSEPETRACOPY, *newMap, 0 ) );
    newA->Import( *A, *newImport, Insert );
    newA->FillComplete();
    RCP<Epetra_MultiVector> newB = rcp( new Epetra_MultiVector( *newMap, B->NumVectors() ) );
    newB->Import( *B, *newImport, Insert );
    RCP<Epetra_MultiVector> newX = rcp( new Epetra_MultiVector( *newMap, X->NumVectors() ) );
    newX->Import( *X, *newImport, Insert );

    // Set the pointers to the new rebalance linear system.
    A = newA;
    B = newB;
    X = newX;
    Map = newMap;
  }

  return (0);
}

Teuchos::RCP<Epetra_CrsMatrix> buildMatrix(int nx, Epetra_Comm & comm)
{
   Epetra_Map map(nx*comm.NumProc(),0,comm);
   Teuchos::RCP<Epetra_CrsMatrix> mat = Teuchos::rcp(new Epetra_CrsMatrix(Copy,map,3));

   int offsets[3] = {-1, 0, 1 };
   double values[3] = { -1, 2, -1};
   int maxGid = map.MaxAllGID();
   for(int lid=0;lid<nx;lid++) {
      int gid = mat->GRID(lid);
      int numEntries = 3, offset = 0;
      int indices[3] = { gid+offsets[0],
                         gid+offsets[1],
                         gid+offsets[2] };
      if(gid==0) { // left end point
         numEntries = 2;
         offset = 1;
      }            // right end point
      else if(gid==maxGid)
         numEntries = 2;

      // insert rows
      mat->InsertGlobalValues(gid,numEntries,values+offset,indices+offset);
   }

   mat->FillComplete();
   return mat;
}

int fevec4(Epetra_Comm& Comm, bool verbose)
{
  int NumElements = 4;
  Epetra_Map     Map(NumElements, 0, Comm);
  Epetra_FEVector x1(Map);
  const double value = 1.;
  x1.PutScalar (value);
				// replace one element by itself. processor 0
				// does not own this element
  const int GID = 3;
  x1.ReplaceGlobalValues(1, &GID, &value);
  x1.GlobalAssemble (Insert);

  if (Map.MyGID(3)) {
    //insist that the value for GID==3 is 1:
    if (std::abs(x1.Values()[Map.LID(3)] - 1) > 1.e-9) return -1;
  }

  std::cout << x1;

  Comm.Barrier();

				// re-apply GlobalAssemble. Nothing should
				// happen
  x1.GlobalAssemble (Insert);
  std::cout << x1;
  if (Map.MyGID(3)) {
    //insist that the value for GID==3 is 1:
    if (std::abs(x1.Values()[Map.LID(3)] - 1) > 1.e-9) return -1;
  }

  return 0;
}

int HypreFileToCrsMatrix(const char *filename, const Epetra_Comm &comm, Epetra_CrsMatrix *&Matrix){
  int MyPID = comm.MyPID();
  // This double will be in the format we want for the extension besides the leading zero
  double filePID = (double)MyPID/(double)100000;
  std::ostringstream stream;
  // Using setprecision() puts it in the string
  stream << std::setiosflags(std::ios::fixed) << std::setprecision(5) << filePID;
  // Then just ignore the first character
  std::string fileName(filename);
  fileName += stream.str().substr(1,7);
  // Open the file
  std::ifstream file(fileName.c_str());
  string line;
  if(file.is_open()){
    std::getline(file, line);
    int ilower, iupper;
    std::istringstream istream(line);
    // The first line of the file has the beginning and ending rows
    istream >> ilower;
    istream >> iupper;
    // Using those we can create a row map
    Epetra_Map RowMap(-1, iupper-ilower+1, 0, comm);
    Matrix = new Epetra_CrsMatrix(Copy, RowMap, 0);
    int currRow = -1;
    int counter = 0;
    std::vector<int> indices;
    std::vector<double> values;
    while(!file.eof()){
      std::getline(file, line);
      std::istringstream lineStr(line);
      int row, col;
      double val;
      lineStr >> row;
      lineStr >> col;
      lineStr >> val;
      if(currRow == -1) currRow = row; // First line
      if(row == currRow){
        // add to the vector
        counter = counter + 1;
        indices.push_back(col);
        values.push_back(val);
      } else {
        Matrix->InsertGlobalValues(currRow, counter, &values[0], &indices[0]);
        indices.clear();
        values.clear();
        counter = 0;
        currRow = row;
        // make a new vector
        indices.push_back(col);
        values.push_back(val);
        counter = counter + 1;
      }
    }
    Matrix->InsertGlobalValues(currRow, counter, &values[0], &indices[0]);
    Matrix->Comm().Barrier();
    Matrix->FillComplete();
    file.close();
    return 0;
  } else {